Failed to find anything much wrong with the tape decks, but they need a new set of drive belts and maybe they would start working again if they had that — except for the missing pinch roller (which I vaguely remember falling off, though I've no idea where it actually is now) and the non-closing cassette door (owing to a missing plastic lug which could probably be reconstructed in some fashion). However, what's wrong with the CD player is that the motor that's supposed to spin the CDs doesn't (although I've no way of knowing whether it's the motor itself or the circuit that controls it which is broken).
It's going to cost an arm and a leg to get it repaired properly, isn't it?